<!DOCTYPE html>
<html>
<head>
    <title></title>
    <meta charset='utf-8'>
</head>
<body>
    <button onclick="alert('啊啊')" id='btn5'>点我</button>

    <button id='btn'>戳我啊</button>
    <button id='btn1'>砍我啊</button>
    <hr>
    <button id="jt">监听</button>
    <hr>
    <button id="remove">接触绑定</button>
</body>



    <script>
        var btn = document.getElementById('btn');
        var btn1 = document.getElementById('btn1');
        btn.onclick =function(){
            alert('戳你妹');
        }

        function demo(){
            alert('砍你妹');
        }
        btn1.onclick = demo;


        var jt = document.getElementById('jt');
        if(jt.addEventListener)
        {
            jt.addEventListener('click',demo,false);
            jt.addEventListener('click',function(){
                alert('你TM还砍');
            },false);
        }else{
            jt.attachEvent('onclick',function(){
                alert('你TM还砍');
            });
            jt.attachEvent('onclick',demo);   
        }

        var remove = document.getElementById("remove")
        remove.onclick = removeClick;

        function removeClick()
        {
            // btn1.onclick = function(){};
            // btn.oncilck = '';//NO
            // btn.onclick = null;
            jt.removeEventListener('click',demo);
        }
    </script>
</html>